The effect of bortezomib on expression of inflammatory cytokines and survival in an experimental sepsis model induced by cecal ligation and puncture

Abstract

Bortezomib can modulate the inflammatory process through the nuclear factor-kappa B (NF-κB) signaling pathway. Although only a clinically used proteasome inhibitor, the immunomodulatory effect of pre-incubated bortezomib is not fully evaluated in inflammation caused by infectious agents. The effect of bortezomib on the expression of inflammatory cytokines in lipopolysaccharide (LPS)-stimulated cells was evaluated using an in vitro cell line experiment. Bortezomib was pre-applied 1 h before LPS stimulation in RAW 264.7 cells. Subsequently, cellular viability as well as various inflammatory cytokines or cellular adhesion molecule levels were measured by reverse transcription-polymerase chain reaction. In addition, nitric oxide (NO) concentration was measured. C57BL/6J mice were used for in vivo cecal ligation and puncture (CLP)-induced murine peritonitis sepsis model experiments. For the negative control, mice received neither surgery nor treatment, and were administered 1 mL of normal saline 1 h before sham surgery. The positive control mice received 1 mL of normal saline 1 h before CLP surgery. To evaluate the impact of bortezomib dose on survival, each group that received bortezomib 0.01 mg/kg or 0.1 mg/kg 1 h before CLP surgery was compared with the positive control. To evaluate the effect of delayed administration of bortezomib on survival, the mice that were administered bortezomib 0.01 mg/kg at 24 h after CLP surgery were compared with the positive control. The mice were assessed for survival up to seven days following surgery, and then mortality rates were compared between groups. All mice that were alive at day seven after surgery in each group were anesthetized to observe the histopathologic findings and measure pulmonary inflammatory score. Pre-incubation with bortezomib (25 or 50 nM) before LPS (50 or 100 ng/mL) stimulation significantly recovered the number of viable RAW 264.7 cells compared with no pre-incubation. The bortezomib decreased the inflammatory cytokines of TNF-α, IL-1β, IL-6, and IL-10, ICAM-1, as well as NO production in LPS-stimulated cells. The seven-day survival rate in mice administered bortezomib 0.01 mg/kg at 1 h before CLP surgery was significantly higher than in the mice treated with normal saline 1 h before CLP surgery. The administration of bortezomib 0.01 mg/kg 1 h before CLP surgery resulted in the significant decrease of lung parenchymal inflammation. In conclusion, pretreatment with bortezomib showed an increased survival rate and a change of inflammatory mediators. This study suggests the possibility of the pretreatment of bortezomib as the new therapeutic target for overwhelming inflammation characterized in severe sepsis.